Latest Articles Include:
- Editorial board and publication information
- Biol Conserv 142(6):IFC (2009)
- Conserving the hottest of the hotspots
- Biol Conserv 142(6):1137 (2009)
- Conservation issues in the Brazilian Atlantic forest
- Biol Conserv 142(6):1138-1140 (2009)
- The Brazilian Atlantic Forest: How much is left, and how is the remaining forest distributed? Implications for conservation
- Biol Conserv 142(6):1141-1153 (2009)
The neotropical Atlantic Forest supports one of the highest degrees of species richness and rates of endemism on the planet, but has also undergone a huge forest loss. However, there exists no broad-scale information about the spatial distribution of its remnants that could guide conservation actions, especially when systematic biodiversity data are not available. In this context, our objectives were to quantify how much of the forest still remains, and analyze its spatial distribution. We considered the entire Brazilian Atlantic Forest, and eight sub-regions, defined according to species distribution. The results revealed a serious situation: more than 80% of the fragments are <50 ha, almost half the remaining forest is <100 m from its edges, the average distance between fragments is large (1440 m), and nature reserves protect only 9% of the remaining forest and 1% of the original forest. On the other hand, our estimates of existing Atlantic Forest cover were higher t! han previous ones (7–8%), ranging from 11.4% to 16%. The differences among estimates are mainly related to our inclusion of intermediate secondary forests and small fragments (<100 ha), which correspond to approximately 32–40% of what remains. We suggest some guidelines for conservation: (i) large mature forest fragments should be a conservation priority; (ii) smaller fragments can be managed in order to maintain functionally linked mosaics; (iii) the matrix surrounding fragments should be managed so as to minimize edge effects and improve connectivity; and (iv) restoration actions should be taken, particularly in certain key areas. The clear differences in the amount remaining and its spatial distribution within each sub-region must be considered when planning for biodiversity conservation.
- Long-term erosion of tree reproductive trait diversity in edge-dominated Atlantic forest fragments
- Biol Conserv 142(6):1154-1165 (2009)
Habitat loss and fragmentation promote relatively predicable shifts in the functional signature of tropical forest tree assemblages, but the full extent of cascading effects to biodiversity persistence remains poorly understood. Here we test the hypotheses that habitat fragmentation (a) alters the relative contribution of tree species exhibiting different reproductive traits; (b) reduces the diversity of pollination systems; and (c) facilitates the functional convergence of reproductive traits between edge-affected and early-secondary forest habitats (5–32 years old). This study was carried out in a severely fragmented 670-km2 forest landscape of the Atlantic forest of northeastern Brazil. We assigned 35 categories of reproductive traits to 3552 trees (DBH greater-or-equal, slanted 10 cm) belonging to 179 species, which described their pollination system, floral biology, and sexual system. Trait abundance was calculated for 55 plots of 0.1 ha across four habitats: fo! rest edges, small forest fragments (3.4–83.6 ha), second-growth patches, and core tracts of forest interior within the largest available primary forest fragment (3500 ha) in the region. Edge-affected and secondary habitats showed a species-poor assemblage of trees exhibiting particular pollination systems, a reduced diversity of pollination systems, a higher abundance of reproductive traits associated with pollination by generalist diurnal vectors, and an elevated abundance of hermaphroditic trees. As expected, the reproductive signature of tree assemblages in forest edges and small fragments (edge-affected habitats), which was very similar to that of early second-growth patches, was greatly affected by both habitat type and plot distance to the nearest forest edge. In hyper-fragmented Atlantic forest landscapes, we predict that narrow forest corridors and small fragments will become increasingly dominated by edge-affected habitats that can no longer retain the full compl! ement of tree life-history diversity and its attendant mutuali! sts.
- Time-lag in biological responses to landscape changes in a highly dynamic Atlantic forest region
- Biol Conserv 142(6):1166-1177 (2009)
Time-lagged responses of biological variables to landscape modifications are widely recognized, but rarely considered in ecological studies. In order to test for the existence of time-lags in the response of trees, small mammals, birds and frogs to changes in fragment area and connectivity, we studied a fragmented and highly dynamic landscape in the Atlantic forest region. We also investigated the biological correlates associated with differential responses among taxonomic groups. Species richness and abundance for four taxonomic groups were measured in 21 secondary forest fragments during the same period (2000–2002), following a standardized protocol. Data analyses were based on power regressions and model selection procedures. The model inputs included present (2000) and past (1962, 1981) fragment areas and connectivity, as well as observed changes in these parameters. Although past landscape structure was particularly relevant for trees, all taxonomic groups (exce! pt small mammals) were affected by landscape dynamics, exhibiting a time-lagged response. Furthermore, fragment area was more important for species groups with lower dispersal capacity, while species with higher dispersal ability had stronger responses to connectivity measures. Although these secondary forest fragments still maintain a large fraction of their original biodiversity, the delay in biological response combined with high rates of deforestation and fast forest regeneration imply in a reduction in the average age of the forest. This also indicates that future species losses are likely, especially those that are more strictly-forest dwellers. Conservation actions should be implemented to reduce species extinction, to maintain old-growth forests and to favour the regeneration process. Our results demonstrate that landscape history can strongly affect the present distribution pattern of species in fragmented landscapes, and should be considered in conservation planni! ng.
- The challenge of maintaining Atlantic forest biodiversity: A multi-taxa conservation assessment of specialist and generalist species in an agro-forestry mosaic in southern Bahia
- Biol Conserv 142(6):1178-1190 (2009)
Recent developments have highlighted the importance of forest amount at large spatial scales and of matrix quality for ecological processes in remnants. These developments, in turn, suggest the potential for reducing biodiversity loss through the maintenance of a high percentage of forest combined with sensitive management of anthropogenic areas. We conducted a multi-taxa survey to evaluate the potential for biodiversity maintenance in an Atlantic forest landscape that presented a favorable context from a theoretical perspective (high proportion of mature forest partly surrounded by structurally complex matrices). We sampled ferns, butterflies, frogs, lizards, bats, small mammals and birds in interiors and edges of large and small mature forest remnants and two matrices (second-growth forests and shade cacao plantations), as well as trees in interiors of small and large remnants. By considering richness, abundance and composition of forest specialists and generalists, ! we investigated the biodiversity value of matrix habitats (comparing them with interiors of large remnants for all groups except tree), and evaluated area (for all groups) and edge effects (for all groups except trees) in mature forest remnants. Our results suggest that in landscapes comprising high amounts of mature forest and low contrasting matrices: (1) shade cacao plantations and second-growth forests harbor an appreciable number of forest specialists; (2) most forest specialist assemblages are not affected by area or edge effects, while most generalist assemblages proliferate at edges of small remnants. Nevertheless, differences in tree assemblages, especially among smaller trees, suggest that observed patterns are unlikely to be stable over time.
- Land use vs. fragment size and isolation as determinants of small mammal composition and richness in Atlantic Forest remnants
- Biol Conserv 142(6):1191-1200 (2009)
The remaining Atlantic Forest fragments are structurally isolated by a matrix of pastures, plantations, or urban areas, and most remnants are small (<100 ha). Island biogeography theory has been used to predict the effects of such fragmentation in the remaining fragments, but human activities and land use around fragments may be equally important. A related question is which aspects of land use have a strong effect on biodiversity. We compare the relative importance of fragment size and isolation vs. land use around fragments as determinants of composition and richness of small mammals in Atlantic Forest fragments. We also compare two aspects of land use around fragments, economic activity (peri-urban, agriculture, cattle), and property ownership (peri-urban, low income rural producers, affluent rural producers). Small mammals were surveyed in 21 fragments varying from 12 to 250 ha, and in two sites of continuous forest in the Macacu River watershed, State of Rio de Ja! neiro, Brazil, from 1999 to 2007. The effects of land use, fragment size and isolation were formulated as eleven candidate models, compared by Akaike Information Criteria. In the models selected, species composition was associated more strongly with fragment size, followed by isolation, with a smaller effect of property ownership. Species richness was determined mostly by fragment isolation, but also by a negative effect of agriculture when it was the dominant economic activity. Regardless of the critics to island biogeography theory, fragment isolation and size were by far the most important determinants of species composition. Economic activity and property ownership allowed the detection of subtle but important effects of land use on species composition and richness.
- Plant communities at the periphery of the Atlantic rain forest: Rare-species bias and its risks for conservation
- Biol Conserv 142(6):1201-1208 (2009)
Initiatives that establish species rarity as an indicator of conservation priority might be biased if they disregard important evolutionary and adaptive processes taking place in lower diversity communities and ecotones. Conservation policies regarding the Atlantic forest strongly emphasize the core formation (i.e. the rainforest stricto sensu) rather than the marginal habitats (e.g. restingas, swamps, and high altitude campos) and species that are rare/endemic. To discuss this issue I revisit a hypothesis I have forwarded in 2002 that postulates that plant colonization of habitats marginal to the Atlantic rain forests of the State of Rio de Janeiro was largely related to terrestrial nurse plants that originally, in the rainforest habitat, were canopy plants such as epiphytes or hemi-epiphytes. Adaptations to water and nutrient restrictions, typical of life in the canopy, granted success to such plants upon migration to sandy, swampy or rocky substrates in neighbouring! areas. Many such species, then, behaved as nurse plants and favoured colonization of these more extreme habitats by a number of other rainforest species. I now review recent evidence that corroborate this hypothesis, while examining the nature of such nurse plants. In all marginal habitats, nurse plants are often highly abundant locally and have high ecophysiological vigour, while both widespread and endemic species are found among them. Thus, nursing effect, local abundance, and ecophysiological performance are not related to species geographic distribution or to their spectrum of habitat preference. Paradoxically, several abundant nurse plant species have low Darwinian fitness. These studies provoke two reflections. First, the Atlantic forest sensu lato, i.e. the core formation plus the peripheral ones, should be treated collectively as a biodiversity hotspot, rather than the core rainforest formation alone. Second, widespread or common species play important functional ! roles in such marginal habitats and, despite their ubiquity, e! cologically they might be less fit than rare/endemic ones at the local level due, for instance, to current constraints to sexual reproduction. Thus, they should also be targeted as conservation priorities.
- Towards an ecologically-sustainable forestry in the Atlantic Forest
- Biol Conserv 142(6):1209-1219 (2009)
Since pristine Atlantic Forest remnants are vanishing, and biological reserves are in short, conservation of biodiversity will largely depend on proper management of the anthropogenic matrix. Here, we test (1) the effectiveness of ecologically-managed tree monocultures in maintaining Araucaria Forest biodiversity, (2) how this effectiveness change among taxa, and (3) we discuss management principles that can be used by the forestry industry in order to contribute positively to biodiversity conservation. The study was conducted in the São Francisco de Paula National Forest, southern Brazil, an environmental mosaic composed mostly of patches of Araucaria Forest and ecologically-managed monocultures of Araucaria, Pinus and Eucalyptus. Using standardized sampling methods in these four main habitats, we have recorded the richness and species composition of small mammals, birds, leaf-litter frogs, butterflies, galling insects, spiders, opiliones, flatworms, woody plants, ep! iphytic angiosperms, epiphytic ferns, lichens, and fruit-body producing fungi. Overall, we recorded 506 species in Araucaria Forest, 181 (36%) of which were exclusive of this habitat while 325 (64%) could be found in at least one monoculture. Distribution patterns of species richness and number of records across taxonomic groups showed that a large biodiversity can be found inside ecologically-managed plantations of Araucaria, Pinus, and Eucalyptus. For all studied taxa, except for epiphytic angiosperms and fruit-body producing fungi, more than half of the Araucaria Forest species could be found living on monocultures. We discuss how the actual management practices of the forest industry can be improved to contribute positively to the conservation of the Atlantic Forest biodiversity.
- Selecting terrestrial arthropods as indicators of small-scale disturbance: A first approach in the Brazilian Atlantic Forest
- Biol Conserv 142(6):1220-1228 (2009)
The growing pressure placed by human development on natural resources creates a need for quick and precise answers about the state of conservation of different areas. Thus, identifying and making use of ecological indicators becomes an essential task in the conservation of tropical systems. Here we assess the effects of small-scale disturbance on terrestrial arthropods and select groups that could be used as ecological indicators in the Brazilian Atlantic Forest. Arthropods were sampled within a continuous forest in the Serra do Mar State Park, southeastern Brazil, both in disturbed and undisturbed areas of the reserve. The abundance of exotic species was higher in the disturbed site, and this pattern seems to be an adequate indicator of anthropogenic disturbance. Species richness of Araneae, Carabidae, Scarabaeidae, Staphylinidae, and epigaeic Coleoptera (pooled) was higher in the undisturbed site, while that of fruit-feeding butterflies was higher in the disturbed si! te. Species richness was not significantly correlated between any pair of taxa. In contrast, species composition was significantly correlated among most groups, and clearly discriminates the disturbed from the undisturbed site. Moreover, fruit-feeding butterflies and epigaeic Coleoptera composition discriminated disturbed and undisturbed sites even when species were grouped into higher taxonomic levels, which may be a way of overcoming the difficulty of identifying arthropod species from poorly studied, species-rich ecosystems. Potential applications for these indicators include the choice and evaluation of sites for the establishment of natural reserves, elaboration of management plans, and the assessment of ecological impacts due to human activities, either for the purposes of licensing or legal compensation.
- Priority areas for the conservation of Atlantic forest large mammals
- Biol Conserv 142(6):1229-1241 (2009)
Large mammal faunas in tropical forest landscapes are widely affected by habitat fragmentation and hunting, yet the environmental determinants of their patterns of abundance remain poorly understood at large spatial scales. We analysed population abundance and biomass of 31 species of medium to large-bodied mammal species at 38 Atlantic forest sites (including three islands, 26 forest fragments and six continuous forest sites) as related to forest type, level of hunting pressure and forest fragment size using ANCOVAs. We also derived a novel measure of mammal conservation importance for each site based on a "Mammalian Conservation Priority index" (MPi) which incorporates information on species richness, population abundance, body size distribution, conservation status, and forest patch area. Mammal abundance was affected by hunting pressure, whereas mammalian biomass of which was largely driven by ungulates, was significantly influenced by both forest type and hunt! ing pressure. The MPi index, when separated into its two main components (i.e. site forest area and species-based conservation index Ci), ordered sites along a gradient of management priorities that balances species-focused and habitat-focused conservation actions. Areas with the highest conservation priority were located in semi-deciduous forest fragments, followed by lowland forests. Many of these fragments, which are often embedded within large private landholdings including biofuel and citrus or coffee crops, cattle ranches and pulpwood plantations, could be used not only to comply with environmental legislation, but also enhance the prospects for biodiversity conservation, and reduce edge effects and hunting.
- On the restoration of high diversity forests: 30 years of experience in the Brazilian Atlantic Forest
- Biol Conserv 142(6):1242-1251 (2009)
We present a review of more than 30 years of ecological restoration in the Brazilian part of the Atlantic Forest. Based on what has been done in this biome, we try to summarize the main findings and challenges for restoration in this highly threatened forest biome. We found that many past experiences did not result in self-perpetuating forests, for different reasons. Currently, most projects aim to construct self-sustaining communities and no longer see restoration as a deterministic process. We also found that the reconstruction of permanent forest with high diversity is feasible but it depends on the strategies applied and on the surrounding landscape. Although many new techniques have been created (e.g. seed rain management or promotion of natural regeneration), the most used one in the Atlantic Forest is still the planting of many native species from different functional groups. Native species are largely used and perform well even in highly disturbed environments.! Today, many projects are trying to produce thousands of hectares of permanent forests and many technical advances are about to be incorporated. But restoration also faces some main challenges to become an effective and widespread means of conserving the Atlantic Forest which are, namely, reducing costs, planning restoration actions at landscape-level, and conforming to socio-political issues. The socio-political tools to overcome such barriers in practice have yet to be developed.